Bi-fold doors have long been used wherever high clearance is needed in a doorway. Bi-fold doors are commonly used in agricultural, industrial, and aviation settings in lieu of the more common track mounted overhead door, as the bi-fold door does not require the same headroom as does the track mounted overhead door, the track mounting system being unnecessary for the bi-fold door.
Opening mechanisms for prior art bi-fold doors commonly use electric motors as the source of the forces needed to open the door. However, electric motors are somewhat limited in their output, the larger motors being somewhat heavy for the application. In addition, it is difficult to operate an electric motor in at varying speeds without losing a significant portion of the power output of the motor. Finally, electric motors are relatively slow in that the amount of torque that they put out allows the typical bi-fold door to be opened only in a steady state, slow manner.
It has been found, however, that a small, self-contained hydraulic door opening mechanism may be used in place of the standard electric motor to overcome the problems inherent in electric motors under such conditions.
It is an objective of the present invention to adapt a hydraulic motor and/or cylinder to open and close a bi-fold door. It is a further object of the present invention to provide a door opening mechanism that can quickly and quietly open a bi-fold door and also actuate automatic locking systems incorporated into the door. It is yet another object of the present invention to simplify the installation of a bi-fold door by pre-assembling the door with its door opening mechanism at the time of manufacture, leaving only the task of mounting the door on its hinges in the door opening and connecting electric power to the door opening mechanism. A final object of the present invention is to provide a hydraulically operated door opening mechanism that may be controlled through a hard-wired control circuit or wirelessly using a suitable transmitter and receiver.
These and other objects, aspects, features and advantages of the present invention will become more fully apparent upon careful consideration of the following Detailed Description of the Invention and the accompanying Drawings, which may be disproportionate for ease of understanding, wherein like structure and steps are referenced generally by corresponding numerals and indicators.
All figures are drawn for ease of explanation of the basic teachings of the present invention only; the extensions of the figures with respect to number, position, relationship, and dimensions of the parts to form the preferred embodiment will be explained or will be within the skill of the art after the following teachings of the present invention have been read and understood. Further, the exact dimensions and dimensional proportions to conform to specific force, weight, strength, and similar requirements will likewise be within the skill of the art after the following teachings of the present invention have been read and understood.
Where used in the various figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the terms “top,” “bottom,” “upper,” “lower,” “first,” “second,” “inside,” “outside,” and similar terms are used herein, it should be understood that these terms have reference only to the structure shown in the drawings as it would appear to a person viewing the drawings and are utilized only to facilitate describing the invention.